Well bore tubing tester



Nov. 10,v 1959 M. B. CONRAD l WELL BoRE TUBING TESTER 2 Sheets-Sheet 1 Filed ilarcn 15, 1955 ,47- 'roe/wey.

Nov. 10, 1959 Filed March 15, 1955 M. B. CONRAD WELL BORE TUBING TESTER 2 Sheets-Sheet 2 IN1/Ewan. MART/N .3. CoA/@A0,

United States Patent WELL BORE TUBING TESTER Martin B. Conrad, Downey, Calif., assignor to Baker Oil Tools, Inc., Los Angeles, Calif., a corporation of California Application March 15, 1955, Serial No. 494,498

22 Claims. (Cl. 251-100) The present invention relates to valve apparatus, and more particularly to valve apparatus adapted to be incorporated in a string of tubing, or the like, for use in a well bore.

It is desirable to test strings of tubing, and the like, to detect the presence of any leaks, as the tubing is being lowered in a well bore. Such testing can be performed by incorporating a valve device in the lower portion of the tubular string, which can be shifted to a closed position at frequent intervals during lowering of the tubing in the well bore to permit pressure to be applied to the fluid in the tubing, and thereby detect the existence and approximate location of any leaks, which, if present, will ordinarily be in the tubing near the top of the well bore, and which, therefore, will enable the defective portion of the tubing to be replaced readily. Between pressure tests, the valve is in a position to allow fluid in the well bore to ow into the tubular string.

It is an object of the present invention to provide an improved valve apparatus particularly suitable for incorporation in a tubular string to be disposed within a well bore, which has a full, unobstructed passage therethrough when in open position to insure unimpeded flow of fluid or movement of other apparatus through the passage. The open passage preferably has a diameter equal to or greater than the inside diameter of the tubular string itself.

Another object of the invention is to provide a valve apparatus adapted to be incorporated in a tubular string to be lowered in a well bore, in which the fluid pressure in the tubular string above the valve apparatus tends to hold the valve in closed position, thereby obviating the need for applying any external forces to maintain the valve closed during a pressure testing or other operation that requires the subjecting of the fluid in the tubular string to pressure.

A further object of the invention is to provide a valve apparatus of the type indicated, in which internal pressure within the tubular string tends to maintain the valve in open position once it has achieved its open state.

A further object of the invention is to providega valve apparatus to be incorporated in a subsurface tubular string, which can be shifted to open position with facility, despite the presence of relatively high pressure differentials in the tubular string tending to maintain the valve apparatus in closed position.

Still another object of the invention is to provide a valve apparatus to be incorporated in a subsurface tubular string, which will open automatically and allow the tubular string to iill with well bore uid during lowering of the tubular string in the well bore. In addition, reverse circulation of iluid down through the well bore annulus `around the tubular string will automatically open the valve, if closed, and allow circulating uid to flow up through the tubular string toward the'top of the well bore.

Another object of the invention is to provide a valve apparatus to be incorporated in a tubular string adapted rice to be run in a well bore, in which the valve apparatus- This invention possesses many other advantages, and

has other objects which may be made more clearly apparent from a consideration of a form in which` it may be embodied. This form isA shown in the drawings accompanying and forming part of the present specification. It will be described inV detail, for Athe purpose of illustrating the general principles of the invention; but it is to be understood that such detailed` description is not to be taken in a limiting sense, since the scope. of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a longitudinal section through a valve apparatus embodying the invention, the parts being shown in elevation, with the valve shown in closed position; t

Fig. 2 is a view similar to Fig. 1, with the valve in; open position; Y

Fig. 3 is a cross-section taken along the lineV3-3 on Fig. l; f

Fig. 4 is a cross-section taken along the line 4-4 on Fig. l;

Fig. 5 is a diagrammatic plan view showing the relative locations of a locking portion of the apparatus and of the pivotal supporting portion of the apparatus for the movable valve head;

Fig. 6 is a longitudinal section taken generally along the line 6--6 on Fig. 5.

The valve apparatus A disclosed in the drawings is ordinarily secured to the lower end of a tubular string B, such as drill pipe or tubing, extending to the top of the well bore, the lower portion of the apparatus, in turn, being secured to a lower tool C, such as a well packer that is to be anchored in packed-off condition in a string of well casing (not shown). During the lowering of the apparatus A, C in the well bore on the tubular string B, it is desired to pressure test the tubular sections and joints to determine the presence of leaks. Accordingly, the valve apparatus A is one which can be closed whenever desired against downward flow of iluid through the tubular string B, which enables fluid pressure to be applied to the fluid therewithin. Following the pressure test, the valve is easily opened, to permit the tubular string to automatically lill with the fluid in the well bore.

As specifically disclosedV in the drawings, the valve apparatus A includes an inner tubular mandrel 10 having an upper threaded pin 11 threadedly secured to the lower end of the tubular string B which extends toY the top of the well bore. The tubular mandrel 10 terminates in a lower valve seat 12 engageable by an upwardly movable Valve head 13 to close the central passage 14 through the mandrel. This valve head 13 is also carried, by the tubular mandrel, being secured to a fulcrum pin 1S that is rotatable within a vertically elongated slot 16 provided in the lower portion of a supporting leg 1 depending from an annular piston 18 whichA is threadedly, or otherwise, secured on the mandrel 10, and which may actually be considered as forming a part thereof.

When permitted to do so, the pivoted valve head ,orY Vllapper valve member 13 can swing downwardly` corn-Y with a circular groove 19 in its upper portion receiving* Patented Nov. 1o, 19759` 3 a rubber, or rubber-like seal ring 20, such as an O ring, which is engageable with and is adapted to seal against the transverse valve seat face.

The mandrel 10, its annular piston l depending supporting leg 17, fulcrum pin l5 and valve head 13 are contained within an outer housing 21, in which they are telescopically arranged. The outer housing 21 includes a cylinder 22, consisting of a cylinder sleeve 23 slidably engaging the periphery of the annular piston i8, this sleeve terminating in an inwardly directed upper cylinder head 24 adapted to slidably engage the periphery of the mandrel l above the piston ES. Fluid is prevented from leaking in an upward direction between the upper cylinder head 24 and the mandrel lll by a seal ring 25, such as a rubber O ring, disposed in an internal circumferential groove 26 in the cylinder head, which slidably seals against the periphery of the mandrel. Similarly, iluid leakage between the piston 18 and the wall of the cylinder sleeve 23 is prevented by providing a suitable seal ring 27, such as a rubber 0 ring, in an external ring groove 28 in the piston, which slidably engages the cylinder Wall. Assurance can be had against leakage of fluid through the threaded connection 29 between the annular piston 18 and the mandrel 10 itself by the provision of a thread seal member 30, in the form of a rubber 0 ring, contained within an internal ring groove 3l in the piston which sealingly engages the periphery of the mandrel lb below the threaded connection.

As explained hereinafter, fluid under pressure is capable of passing from the central mandrel passage t4 through one or more ports 32 provided through the mandrel into the annular cylinder space 33 between the upper cylinder head 24 and the annular piston 18, and between the periphery of the mandrel llt) and the wall of the cylinder sleeve 23. Such fluid under pressure is prevented from leaking out of the cylinder space 33 by the respective seal members 25, 27, 39.

The lower portion of the housing 2l is constituted by a lower head 34 threadedly secured within and to the lower end of the cylinder sleeve 23, this lower head having a lower threaded box 35 to receive the upper threaded end 36 of the tubular member C or central body of a lower tool, such as a well packer that is to be anchored in packed-oftr condition against a well casing. The lower head 34 is tubular and has a passage 37 of an internal diameter substantially the same as the internal diameter through the mandrel l@ and of the tubular string B thereabove, to provide an unobstructed passage through the entire valve apparatus A when the valve head ll3 is in its full open position, such as disclosed in Fig. 2. Leakage of lluid between the lower head 34 and cylinder sleeve 23 may be insured against by a thread seal 38, which may be in the form of a rubber O ring, disposed Within a circumferential groove 39 in the head and sealingly engaging the wall of the cylinder sleeve.

Movement of the valve head 13 between open and closed positions is secured by the telescopic movement of the mandrel lil with respect to the outer housing 2l. As. the mandrel 16 moves upwardly and downwardly within the outer housing 21, it carries the dapper vaave member 13 with it, inasmuch as the latter is secured on the fulcrum pin l which is mounted within the supporting leg 17 attached to the piston 18, which is, in turn, secured to the mandrel l0. The relative longitudinal movement between the mandrel and the outer housing 2l enables the valve to be shifted to open position positively and held in such position positively. The positive shifting of the valve head i3 to open position is accomplished upon relative upward movement of the mandrel 1G within the outer housing 2l by causing a cam member 40, in the form of a sleeve secured to the outer housing 2i, to engage and shift the valve head 13 to open position.

As specifically disclosed, the cam sleeve 40 extends only part way around the circumference of the apparatus.

its internal diameter being slightly greater than the external diameter of the lower mandrel portion llt), to allow the latter to slide thereinto. The cam sleeve il@ is cut away on opposite sides of the supporting leg ll7 depending from the piston 18, to provide an arcuately shaped chamber 4l allowing the leg to move downwardly and upwardly between the adjacent longitudinal ends 42 of the cam sleeve (Fig. 3). These end surfaces a2 of the cam sleeve i0 actually are only present in the upper portion of the sleeve, being adapted to engage the sealing face 13a of the valve head 13 and hold the latter in its open position completely out of the path of the fluid moving through the mandrel and lower head passages tfl, 37. From the longitudinal holding surfaces 42, the cam sleeve dit has the downward and inwardly directed curve cam surfaces i3 that are engageable with the sealing face 13a of the valve head to shift it to open position as the mandrel lll moves upwardly relative to the housing 2l and the sleeve 4t? secured thereto. These cam surfaces 43 terminate in a transverse shoulder 413 provided by a bore l5 of the sleeve therebelow of en*- larged diameter. When the valve head 13 is disposed within this enlarged diameter portion 45, it can engage the valve seat l2 at the lower end of the mandrel. When in this closed position, the lower surface i311 of the valve head rests upon a supporting shoulder 46 at the upper portion of the lower head 34, this shoulder extending part way around the axis of the apparatus and engaging the valve head t3 at its peripheral marginal portion. The valve head i3 itself has a substantially greater diameter than the outside diameter of the lower peripheral portion of the mandrel valve seat l2, so that the marginal portions of the inner face 33a of the valve head are capable of engaging the cam surfaces 43 on the sleeve 4t? to be shifted thereby to an open position.

The valve member 13 is moved from an open position toward a closed position upon relative downward movement of the mandrel lt) within the valve housing 2l, by virtue of engagement of a tapered surface 5@ on the valve head with the upper end of a lower head projection 51, which will cam the valve head 13 in an inward direction, as it moves downwardly within the housing 21, toward the horizontal position shown in Fig. l. When fully disposed in the horizontal position, the lower surface i311 of the valve head will engage the supporting shoulder 46 extending almost completely around the valve head except for the removal of the material necessary to accommodate the portion of the Valve head adjacent the fulcrum pin l5, the valve seat l2 on the lower end of the mandrel engaging the sealing surface 13a of the valve head and the seal ring 19. Proper full engagement between the lower surface 13b of the valve head and supporting shoulder 46 and of the valve seat l2 with the sealing face 13a of the valve head 113 and the seal ring i9 is assured by loosely titting the fulcrurn pin i5 within the slot 16 of the depending supporting leg 1.7, which will thereby allow the lower surface lb of the valve head to engage the supporting shoulder d6 and then permit the mandrel l0 to still move downwardly relative to the valve head 13 to a slight extent to insure proper seating of the valve seat l2 against the upper surface 13a of the valve head and the seal ring 19.

When the mandrel ll@ is moved upwardly relative to the housing, it will allow the valve head 13 to swing downwardly about the axis of the fulcrum pin l5 to an open position, the valve head EL3 engaging the cam surfaces 43 to positively insure movement of the head to fully open position, and its retention in such position by the longitudinal holding surfaces 42.

The valve operating sleeve 40 is separate from the lower head 34, although secured thereto. It is attached to the latter by providing a segmental external groove 52 part way around the lower head 34 which is adapted to receive a companion internal rib 53 on the lower portion ofthe cam actuating sleeve 40. The lower head groove 52 is locatedl substantially diametrically opposite'the fulcrum:

pin and depending leg 17 of the mandrel structure, which will then allow the sleeve 40 to be inserted within the head 34, with its lower rib 53 disposed diametrically opposite the groove 52, whereupon the sleeve 40 can be rotated to cause its rib 53 to enter the groove 52, and with the cam surfaces 42, 43 disposed in their Vproper position relative to the valve head 13.

Despite the fact that the valve head 13 closes in an upward direction against the lower end 12 of the mandrel 10 and moves relatively downward with respect thereto to open position, a Huid pressure dilerential within the mandrel 10 cannot shift the valve head 13 downwardly from its companion seat 12. This is due to the relationship between the effective area of the upper valve head surface 13a, which is the area S disclosed in Fig. 1, across the innermost sealing circumference of the seal ring 19 against the valve seat 12, and the annular area R between periphery of the mandrel 10 above the piston 18 and the wall 23a of the cylinder 22. This latter area R is made greater than the area S, so that with a pressure differential within the mandrel 10 such pressure will act over a greater area R, exerting a greater downward force on the annuular piston 18 to holdthe mandrel 10 downwardly with the valve seat 12 in engagement with the sealing face 13a of the valve head and seal ring 19, than the total force provided by the uid pressure acting over the cross-sectional area S and tending to urge the mandrel 10 upwardly away from the head 13.

The valve head itself is backed up solidly by the shoulder 46 on the lower cylinder head 34, which prevents the latter from moving away from this head. Moreover, the liuid pressure diierential internally of the mandrel 10 is also acting on the fluid in the cylinderl space 33 and in an upward direction against the cylinder head 24, urging the entire cylinder 22 and housing 21 in an upward direction, which will also hold the valve head 13 upwardly against its seat 12. In effect, the fluid pressure is acting over the area R in a downward direction on the annular piston 18 to urge the mandrel downwardly and also in an upward direction over the upper cylinder head 24, urging the housing 21 in an upward direction, thereby moving the lower cylinder head 34 and the mandrel 10 toward each other to firmly clamp the valve head 13 therebetween and prevent its opening. The area S, being smaller than the area R, cannot have a sufficient total hydraulic force acting on it to shift the valve head 13 downwardly relative to the mandrel 10, to swing it to open position.

It is, accordingly, evident that the hydraulic pressure within the apparatus tends to keep the valve in closed position. Even in the presence of relatively high pressure differentials within the apparatus, it is easily shifted to open position, since it takes only a slight upward movement of the mandrel 10 relative to the housing 21 to elevate the valve seat 12 above the sealing face 13a of the valve head 13. Assuming only a slight separation takes place, the fluid pressure is capable of acting'on'the underside or seat 12 of the mandrel and also on the lower surface of the annular piston 18, which will then tend to urge and maintain the mandrel 10 in an upward and open position. Thus, as soon as the mandrel 10 is elevated slightly with respect to the housing 21, the fluid presl sure within the mandrel may still be acting upon the upper end of the annular piston 18 over the area R, urging the mandrel in a downward direction, but it is also acting in an` upward direction over the entire cross-sectional area W of the mandrel 10 and its piston 18, tending to elevate the parts relative to the housing.Y In addition, the uid pressure will be acting over the annular area T of the lower cylinder head 34 between the wall of its passage 37 and the cylinder wall 23a, which is a greater area than the area R over which the fluid pressure is acting in an upward direction on the upper cylinder head 24. Accordingly, the fluid pressure will be acting in a resultant downward direction onV the housing A21, tending to shift it'down-V wardly of the mandrel 10. Such downward movement will cause the cam surfaces 43 to engage the valve head 13,

and swing it to its fully open position, as disclosed in Fig. 2.

With the parts in the open position, any uid pressure within the passage 14 will tend to hold the apparatus in this open position because of the area relationships described above. Thus, the iiuid pressure will still be acting in an upward direction over the mandrel 10 and its annular piston 18 over the cross-sectional area W, tending to urge the latter upwardly relative to the housing 21, and it will be acting in a downward direction on the outer housing 21 over the area T minus the area R, tending to hold the outer housing in a downward position. The relative downward movement of the housing 21 with respect to the mandrel is limited to the position in which the longitudinal surfaces 42 engage the valve head 13 to keep it in open position by engagement of the upper end of the piston 18 with the upper cylinder head 24.

Although the fluid within the valve apparatus Aitself tends to keep it in open position, it might be desirable to positively lock the valve apparatus in such open position. Accordingly, the apparatus incorporates a lock device. Such device includes a depending locking leg 60 integral with, or otherwise secured to, the annular piston 18 substantially diametrically opposite the valve head supporting leg 17. This depending leg 60 is adapted to be received within a longitudinal slot 61 formed jointly within an upwardly projecting portion 62 of the lower cylinder head 34 and in the cam sleeve 4t). When the lock leg 60 is disposed in alignment with such groove or slot 61, the mandrel 10 can be shifted downwardly relative to the housing 21, to close the valve. However, upon elevation `of the mandrel 10 relative to the outer housing 21, the lower end of the lock member 60 is disposed above the upper end of the slot 61, permitting the mandrel 10 to be rotated a partial revolution to align the leg 60 with a recess 63 in the upper portion of the cylinder head projection 62. When so aligned, the valve head 13 is in its fully open position, such as disclosed in Fig. 2, and the mandrel 10 cannot be moved downwardly within the housing 21 to any substantial extent, or to a position that will allow the valve head 13 to shift from its fully open position.

The locking leg 60 is positively located in alignment with the slot 61 or in alignment with the recess 63. Thus, the left wall 64 of the slot 61 extends above the upper end 65 of the slot itself, so that upon rotation of the mandrel in a clockwise direction, or to the right, the left side of the leg 60 will engage such locating wall 64, advising the operator that the lock leg 60 is in alignment with the ,slot 61, and permitting him to lower the mandrel 10 withing the housing 21, for the purpose of closing the valve head 13 against its companion seat 12. Elevation of the mandrel -10 within the housing 21 to its fullest extent, as determined by engagement of the piston 18 with the upper cylinder head 24, will permit the mandrel 10 to be rotated in the opposite direction, or to the left, the right side 60 of the leg then engaging a wall 66 or upwardly eX- tending projection on the lower cylinder head portion'62, which will locate the leg 68 in alignment with the shallow recess 63, allowing the operator to lower the mandrel 10, which can only occur very slightly, to dispose the end of the leg in the recess 63 and insure that it will not leave such recess inadvertently during lowering ofthe apparatus in the well bore.

1t is, thus, apparent that the lock structure will positively hold the valve in open position and preclude inadvertent shifting of the parts to permit the valve to close. In addition to this function, the locking structure also permits rotary motion of the tubular string B and mandrel 10 to be transferred to the outer housing 21, for transmission to the lower tool C. It is evident that when theleg 60 is disposed within the slot 61, any rotation of the mandrellQ will be transferred through the leg 60 to the lower` head 34, `and from the latter to the body of the lower tool C.

ln the use of the apparatus, it is connected to the tubular string B with its lower end usually connected to the lower tool C. This lower tool may have friction drag devices (not shown) incorporated in it that resist its longitudinal movement within the well casing in which the apparatus is being run, and which will, therefore, impose a certain resistance to longitudinal movement ot the outer housing 21 in the casing. The lock leg o@ is preferably disposed within the holding recess 63, to insure that the valve apparatus is in open position during its lowering in the well casing or well bore. When it is desired to test the tubular string, it is elevated slightly, to remove the lock leg 6d from the recess 63, whereupon the tubular string B and mandrel it? are rotated slightly to the right until the leg 69 engages the locating wall 64 of the slot, whereupon the tubular string and mandrel can be lowered, to cause the cam surface Sti on the valve head 13 to engage the projection l of the lower cylinder head 34, to shift the valve head toward its closed position, with the outer surface 13b of the head solidly engaging the shoulder and the valve seat l2 sealingly engaging the sealing face 13a of the valve head and the seal i9. Such relative movement can occur readily, inasmuch as the friction drag device of the lower tool C will resist downward movement of the housing 2li within the well casing.

Pressure can now be applied to the fluid in the tubular string B, the valve head 13 preventing the huid from passing its sealing location against the valve seat 12. The pressure will also pass through the mandrel ports 32 into the cylinder space 33, acting in an upward direction on the upper cylinder head 24 and in a downward direction on the annular piston 18, holding the valve head i3 closed against its companion seat t2, despite the action of the pressure in a downward direction on the valve head 13 tending to force it away from its companion seat. This is due to the fact, as explained above, that the area R is substantially greater than the area S.

When it is desired to open the valve, the pressure within the tubular string B and mandrel lt can be bled off, if desired, and the mandrel elevated with respect to the housing 2i. Such elevating movement will permit the valve head "13 to drop away from its seat i2. In any event, it is shifted to fully open position by the camming action of the Cam surface 43 against its inner face 13a, which will swing it to a fully open position completely out of the path of any liuid that might be moving through the passage le, 37 of the valve apparatus. Downward movement of the valve apparatus can continue, the valve tending to remain in its open position. if desired, the tubular string B and mandrel lll can be turned slightly to the left to relocate the lock leg 6i) in alignment with the recess 63, the leg then dropping into the latter to hold the parts in open position.

The foregoing closing and opening of the valve can occur as often as desired, the valve being positively closed and also being held positively in an open position. Even if the valve is in closed position and the mandrel l@ is not elevated within the housing 2l, to shift the valve to open position, its opening will occur automatically merely by relieving the interior of the mandrel of pressure and by lowering the apparatus in the well bore. With the valve closed, the hydrostatic head of iluid externally of the well casing will pass upwardly through the body of the lower tool C into the housing structure 2l below the valve head i3 and the piston The fluid under pressure will act in a downward direction over the area T of the lower head 34, and will shift the lower head and entire housing 21 in a downward direction. Thus, the huid pressure will shift the housing 2l downwardly to fully open the valve, placing the parts in the position disclosed in Fig. 2. Similarly, even in the absence of any hydrostatic head differential between the huid internally and externally of the tubular string, the applica-- tion of pressure to the fluid in the annulus around the tubular string, as by reversely circulating the uid down through such annulus, will cause the valve to automatically open, whereupon the circulating uid can pass upwardly through the open valve apparatus A and into the tubular string B toward the top of the well bore.

The inventor claims:

1. In a valve apparatus adapted to be incorporated in a tubular string to be disposed in a well bore: inner and outer tubular members telescopically arranged with respect to each other; a valve seat ou said inner member; a valve element movable laterally with respect to said members into and out of engagement with said seat; means for disposing said valve element adjacent to said seat; and means engageable with said valve element in response to relative extensible telescopic movement between said members to shift said valve element laterally of said member in a direction away from and completely to one side of said seat.

2. In a valve apparatus adapted to be incorporated in a tubular string to be disposed in a well bore; inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element carried by said inner member and movable relative thereto into and out of engagement with said seat; and means on said outer member engageable with said valve element in response to relative contractible telescopic movement between said members to shift said valve element toward said seat.

3. In a valve apparatus adapted to be incorporated in a tubular string to be disposed in a well bore: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element carried by said inner member and movable relative thereto into and out of engagement with said seat; and means on said outer member engageable with said valve element in response to relative telescopic movement between said members to shift said valve element toward engagement with said seat.

4. In a valve apparatus adapted to be incorporated in a tubular string to be disposed in a well bore; inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element carried by said inner member and movable relative thereto into and out of engagement with said seat; and means on said outer member engageable' with said valve element in response to relative extensible telescopic movement between said members to shift said valve element in a direction away from said seat.

5. in a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on one of said members; a valve element movable laterally with respect to said members into and out 0f engagement with said seat; means for disposing said valve element adjacent to said seat; means engageable with said valve element in response to relative telescopic movement between said members to shift said valve element laterally with respect to said seat; and holding means on the other of said members engageable with said valve element to hold said valve element engaged with said seat.

6. In a valve apparatus adapted to be incorporated in a tubular string to be disposed in a well bore: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element carried by said inner member and movable relative thereto into and out of engagement with said seat; means on said outer member engageable with said valve element in response to relative telescopic movement between said members to shift said valve element with respect to said seat; and holding means on said outer member engageable with said valve element to hold said valve element engaged with said seat.

7. ln a valve apparatus adapted to be incorporated ini a tubular stringv to be disposed in a well bore; inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element carried by said inner member and movable relative thereto into and out of engagement with said seat; means on said outer member engageable with said valve element in responses to relative telescopic movement between valve members to shift said valve element with respect to said seat; holding means on said outer member engageable with said valve element to hold said valve element engaged with said seat; and hydraulically operable means on said inner and outer members for urging said valve seat and holding means toward each other to clamp said valve element therebetween.

8. In a valve apparatus adapted to be incorporated in a .tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on one of said members; a valve element movable with respect to said members into and out of engagement with said seat; means for disposing said valve element adjacent to said seat; means engageable with said valve element in response to relative telescopic movement between said members to shift said valve element with respect to said seat; holding means on the other of said members engageable with said valve element to hold said valve element engaged with said seat; and hydraulically operable means on said inner and outer members for urging said valve seat and holding means toward each other to clamp said valve element therebetween.

9. In a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element movable laterally with respect to said members upwardly into engagement with said seat; means for disposing said valve element adjacent to said seat; and holding means on said outer member engageable with said valve element in response to relative telescopic movement between said members to hold said valve element engaged with said seat.

l0. In a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element movable with respect to said members upwardly into engagement with said seat; means for disposing said valve element adjacent to said seat; holding means on said outer member engageable with said valve element in response to relative telescopic movement between said members to hold said valve element engaged with said seat; and hydraulically operable means on said inner and outer members subject to thelluid pressure in said inner member for urging said valve seat and holding means toward each other to clamp said valve element therebetween.

l1. In a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically `arranged with respect to each other; a valve seat on said inner member; a valve element movable with respect to said members upwardly into engagement with said seat; means for disposing said valve element adjacent to said seat; holding means on said outer member engageable with said valve element in response to relative telescopic movement between said members to hold said valve element engaged with said seat; and hydraulically operable means on said inner and outer members subject to the iiuid pressure in said inner member for urging said val-ve seat and holding means toward each other to clamp said valve element therebetween; the cross-sectional area of said inner member at said valve seat being substantially less than the cross-sectional area of said hydraulically operable means subject to said fluid pressure.

12. In a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element movable with respect to said members upwardly into engagementwithY tive telescopic movement between said members to holdv said valve element engaged with said seat; and hydraulically operable means on said inner and outer members subject to the fluid pressure in said outer member below said valve element for urging said valve seat and holding means away from each otherl to enable said valve element to move away from said seat.

13. In a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element pivotally carried by said inner member and swingable upwardly into engagement with said seat; and holding means on said outer member engageable with said valve element i in response to relative longitudinal movement between said members to hold said valve element engaged with said seat.

14. In a Ivalve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element pivotally carried by said inner member and swingable upwardly into engagement with said seat; holding means on said outer member engageable with said valve element in response to relative longitudinal movement between said members to hold said valve element engaged with said seat; and means on said outer member engageable with said valve element upon downward movement ofsaid inner member with respect to said outer member to swing said valve element toward said seat.

15. In a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a

valve seat on said inner member; a valve element pivotally carried by said inner member and swingable upwardly into engagement with said seat; holding means on said outer member engageable with said valve element in response to relative longitudinal movement between said members to hold said valve element engaged with said seat; and means on said outer member engageable with said valve element upon upward movement of said inner member with respect to said outer member to swing said Valve element away from said sea 16. In a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element pivotally carried by said Vinner member and swingable upwardly into engagement with said seat; holding means on said outer memberengageable with said valve element in response to relative longitudinal movement between said members to hold said valve element engaged with said seat; means on said outer member engageable with said valve element upon downward movement of said inner member with respect to said outer member to swing said valve element toward said seat; and means on said outer member engageable with said valve element upon upward movement of said inner member with respect to said outer member to swing said valve element away from said seat.

17. In a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element pivotally carried by said inner member and swingable upwardly into engagement with said seat; holding means on said outer member engageable with said valve element in response to relative longitudinal movement between said members to hold said valve element engaged with said seat; and hydraulically operable means on said inner and outer members subject to the Huid pressure in said inner i ill member for urging said valve seat and holding means towardeach other to clamp said valve element therebetween.

1S. in a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element pivotally carried by said inner member and swingable upwardly into engagement with said seat; holding means on said outer member engageable with said valve element in response to relative longitudinal movement between said members to hold said valve element engage with said seat; means on said outer member engageable with said valve element upon downward movement of said inner member with respect to said outer member to swing said valve element toward said seat; means on said outer member engageable with said valve element upon up ward movement of said inner member with respect to said outer member to swing said valve element away from said seat; and hydraulically operable means on said inner and outer members subject to the fluid pressure in said inner member for urging said valve seat and holding means toward each other to clamp said valve element therebetween.

19. In a valve apparatus adapted to be incorporated in a tubular string: inner and outer tubular members telescopically arranged with respect to each other; a valve seat on said inner member; a valve element pivotally carried by said inner member and swingable upwardly into engagement with said seat; holding means on said outer member engageable with said valve element in response to relative longitudinal movement between said members to hold said valve eiement engaged with said seat; means on said outer member engageable with said valve element upon downward movement of said inner member with respect to said outer member to swing said valve element toward said scat; means on said outer member engageable with said valve element upon upward movement of said inner member with respect to said outer member to swing said valve element away from said seat; and hydraulically operable means on said inner and outer members subject to the Huid pressure in said inner member for urging said valve seat and holding means toward each other to clamp said valve element therebetween; the cross-sectional area of said inner member at said valve seat being substantially less than the cross-sectional area of said hydraulically operable means subiect to said fluid pressure.

20. In a valve apparatus to be incorporated in a tubular string to be disposed in a well bore: inner and outer tubular members telescopically arranged with respect to each other; connecting means on said tubular members for securing each of said tubular members to an adiacent section of the tubular string; a valve seat on said inner tubular member; a valve element movable laterally with respect to said members into and out of engagement with said seat; means for disposing7 said valve element adiacent to said seat and completely to one side ef said seat when out of engagement therewith; means engageable with said valve element in response to relative telescopic movement between said members to shift said valve element laterally with respect to said seat completely to one side of said seat; and coeng'ageable stop means ori said members for limiting the extent of extensible telescopic movement between said members.

2l. In a valve apparatus to be incorporated in a tubular string to be disposed in a well bore: inner and outer tubular members telescopically arranged with respect to each other; connecting means on said tubular members for securing each or said tubular members to an adjacent section of the tubular string; a valve seat on said inner tubular member; a valve element movable laterally with respect to said members into and out of engagement with said seat; means for disposing said valve element adjacent to said seat; means engageable with said valve element in response to relative extensible telescopic movement between said members to shift said valve element laterally in a direction away from said seat completely to one side of said seat; and coengageable stop means on said members for limiting the extent of extensible telescopic move" ment between said members.

22. In a valve apparatus to be incorporated in a tubular string to be disposed in a well bore: inner and outer tubular members telescopically arranged with respect to each other; connecting means on said tubular' members for securing each of said tubular members to an adjacent section of the tubular string; a valve seaton said inner tubular member; a valve element movable laterally with respect to said members into and out of engagement with said seat; means for disposing said valve element adjacent to said seat; means engageable with said valve element in response to relative extensible telescopic movement between said members to shift said valve element laterally in a direction away from said seat; coengageble' stop means on said members for limiting the extent of extensible telescopic movement between said members; and means on said outer member engageable with said valve element in response to relative contractible telescopic movement between said members to shift said valve element laterally toward said seat.

References Cited in the le of this patent UNITED STATES PATENTS 1,314,650 Holt Sept. 2, 1919 1,818,508 Scott Aug. 11, 1931 1,842,869 Hale Jan. 26, 1932 2,447,842 Cameron Aug. 24, 1948 2,492,271 Cox Dec. 27, 1949 2,507,262 McGivern May 9, 1950 2,716,535 Ehlke Aug. 30, 1955 FOREIGN PATENTS 503,054 France Mar. 8, 1920 

